Dipper-stick crowding means for excavators



Feb. 19, 1952 B. CALVERT 2,586,000

DIPPER-STICK CROWDING MEANS FOR EXCAVATORS Filed Sept. 15, 1947 2 SHEETSSHEET 1 IN V EN TOR.

Bert S. Ca/veri dwmafl- Feb. 19, 1952 B. CALVERT 2,586,000

DIPPER-STICK CROWDING MEANS FOR EXCAVATORS Bari S. Ca/yerzf Patented Feb. 19, 1952 mrrsit s'rrok CROWDING MEANS FOR EXOAVATORS Bert Calvert, Los Angeles, Calif. Application September 13, 1047, Serial No; 773,777

..a Claims. (01. 214 1s5) i This invention relates to excavating apparatus, andis, particularly useful when applied'to a type of; excavator sometimes reierredto as' a "power shovel. In its construction. this type of excavator includes aboom usually mountedto swing up and down in a vertical plane, and supported on. a turntable on a tractor. The boom is normally in a more or less inclined position Qn its upper side, usuallya bracket secured to the boom, on

which a guide ;or saddle is pivotally supported to have a limited; swinging movement on a horiozntal axis. 'I;he material such as earth, is removed or dugout bymeans of a dipper that is carried on a handle grfdipperestick that is guided through the saddle. ;When the dipper'is dig ing into a bank,, it} isl ifted by meansjof a fall of hoist line that runs 1 over one or more: sheaves at "the; peak th ;,hQ9m:-. .The a n; un 9 i .l f ne l is guided under a sheaveonthef bbom, and extends back to the interior of the cab over'the tractor where it runs over a drum controlled by the operator of the excavator; the other run passes around sheaves associated with the bracket, and extends up toward the upperend of the stick where it is dead-ended. By deadending this run on the stick at a point considerably above the level of the boom, it will be evident that when the lifting fall connected to the dipper is being raised by its drum, a certain amount of tension will be exerted in the run that is dead-ended on the stick, tending to crowdthe stick downwardly; but this crowding effect is not great until there is considerable tension in. the lifting fall. For this reason until the dipper has bitten into the material or bank that is being excavated, there is only slight tension in the fall to the dipper, and hence the crowding effectin the stick is then due merely to theweight of the stick and dipper, it being understood that at this moment the retractor cable for the stick will be permitted to run free. This retractor cable or line usually is disposed in a loop on the under side of the stick and passes around a sheave near the sticks lower end, and at its rear side. This retractor cable has its own drum, which is in thje cab, and which is also controlled by the operator of the excavator. d

;.One of the objects of this invention is to provide an excavator of this type with means for maintaining and developing a crowding forcein the dipper stick, which'will be more positive in its action, and which will insure that the crowding eifect when the dipper digs into the material, will be sufficient to insure that the dipper will not be deflected from the arc of its swing,

which it should naturally have when the dipperstick swings around the saddle pivot.

Another object of the invention is to provide means whereby the tension in the boom cable that supports the boom, can be utilized to develop a crowding force in the dipper-stick. By this means a relatively greater crowding force can be developed, and furthermore'this force increases automatically for boom positions where the axis of the boomis inclined to a relatively small angle to the ground line.

While the means that I employ for developing this necessary crowding effect in the dipperstick, could be used as the sole means for developing this crowding movement, in the present specification and drawing I have illustrated it employed as an auxiliary crowding means supplementing the action'of the usual crowding line referred to above.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combinations of parts to. be described hereinafter,

all of which contribute to produce an eflicient dipper-stick crowding means for excavators. A preferred embodiment of the invention is described in th'e following specification, while the "the dipper 'and dipper-stick are omitted. The

In ,the 1 drawing;

primarypurpose of this view is to clearly illustrate'th'e ro'ving of the boom cable, and the means which '-I employ with it to develop the crowding tension imthe crowding line.

Fig. 3 is:=a view similar to Fig. l, and this View not only shows the cables illustrated in Fig. l, but

.also shows some of the other cables, namely, the lifting cable for the. dipper, and the usually employed crowding-line. what larger scale than Fig. l, and represents the This view is on a somedipper about to bite into the side of an embankment,;-01 ';bank of material, such as earth. In Fig.

3., Qne of the sheaves on the boom bracket is broken away to show a similar sheave back of it. filefeifring moreparticularly to the parts, and

especially to Figs 1 and 2, l indicates the cab of the excavator, which is of conventional type. This cab is mounted on a turntable 2, which is supported on a caterpillar or cat 3. The framing of the cab l supports the boom 4 to rotate on a horizontal axis at the base pin 5 so that the boom 4 can swing up or down in a substantially vertical plane when such movement is necessary. On the upper side of the boom a saddle bracket 6 is secured, and on the upper end of this bracket a guide or saddle l is pivotally supported on a 4 cable, which constitutes a part of the regular equipment of excavators of this type.

The retractor cable, and lifting cable, illustrated in Fig. 3, will now be described. The retractor cable indicated generally by the reference numeral C, includes a loop 0 that extends down the under side of the dipper-stick, and extends under the sheave 28; and one of the runs forming this loop 0', passes over one of the sheaves 9 referred to above, from which it extends down i in a short end 0 that is dead-ended at 29 on the horizontal shaft or arbor- 8 that also operates as an axle or arbor for a plurality of sheaves indicated generally by the reference numeral 9. These sheaves are usually four in number, and will be referred to more specifically hereinafter. The dipper-stick l 0 is guided to slidewith a controlled movement through the sleeve "I,- and its lower end carries the dipper II, the cutting edge of which is provided with the usual projecting teeth [2 to facilitate the action of the dipper in digging into an. embankment l3, such as illustrated. I

In applying my invention to such an apparatus, I employ a boom cable A, the main run a of which is disposed in a coil on a drum M in the cab (see Fig. 2). This cable also includes a dead-ended run a which is dead-ended at some convenient point such as the anchor IE on the frame of the cab. These two runs a and a pass around corresponding sheaves i5 located at, or adjacent to, the peak of the boom, and from there extend, respectively, into draw runs a and a These draw runs 013 and a extend back to a point over the cab where they pass around j2| rides, said sheave being carried on a block 22.

This sheave 2| is mounted'to rotate in a substantially horizontal plane, and the forward end of the block carries a similar sheave 23, which is mounted to rotate in a substantially vertical plane.

My crowding line, that gets its tension from the loop a will now be described. This line is indicated generally by the reference numeral B, and most of this line is disposed in a crowding loop composed of a lower run I) and an upper run b The lower run 17' passes under the lower side of one of the sheaves 9, which is indicated in Fig. 2 by the numeral, from which point it passes upwardly in acrowding run 17 that is dead-ended at adjacent to the upper end of the dipperstick. The upper run I) of the crowding-loop b extends over the upper and outer side of one of the sheaves9 indicated particularly by the reference numeral 26 in Fig. 2, from which point it extends down in a run b dead-ended. at-21 on the upper side of the boom and adjacentto the bracket 6.

It will be evident by an examination of Figs. 1 and 2, that by reason of'the disposition illustrated, of the cables, the weight of the boom and its load will develop tension in the tension loop a and in the crowding loop composed of the runs b and b As illustrated in Fig. 1, this would develop an unbalanced crowding force, or thrust force, acting downwardly in the stick 10. This force of course is resisted by the retractor upper side of the boom. The other run of the This drum 30 carries a brake 'drum 3|, which is also indicated in dotted lines, which-has a brake band 32 also indicated in dotted lines, connected to a brake lever 33. This drum 30 has a clutch (not illustrated) which, when closed, will permit the power to retract the stick and, slide it up through the siddle guide I.

The dipper line or lifting line to the dipper, will now be described. This line is indicated generally by the reference numeral D, and it includes a falldtd the dipper sheave 34, the runs of which pass uband over two sheaves 35 mounted at the peak of the" boom. One of these runs continues back as a live run d and passes back under a sheave 36 mounted in the bracket 6, from which point it passes in a run d over to its lifting drum 31, of the winch illustrated in dotted lines. The other run of the lifting cable that passes back down the boom, passes around a sheave 38 alongside of the sheave 36 from which it passes back toward the stick in a run it that passes underthe fourth loose sheave of the sheave group 9, from whichpoint:itjpasses'upwardly in a dead-ended run it that is dead-ended at 39 on the side of the 'dipper-sticknear its upper end.

The mode of operation of the complete equipment with the complete cable illustrated in Fig. 3, will now be described. With the dipper H dropped onto the ground in the position illustratedin Fig 3, the operator closes the clutch of the dipper hoistiwhich takes up cable in the loop d, and this of course rotates the dipper-stick around the axis of the arbor 8 so that the teeth I2 on the dipper, will substantially describe an are such as illustrated by the dotted line 40, and this of course should fill the dipper. The crowding lines insurethat the dipper will not be pushed back from this are by the bank 13. This is assured by reason of the fact that the tension in the tension loop a (see Fig. 2) is constantly maintained by the boom and the load carried by it; The tension in the loop a will be greatest of course when the boom is disposed at a small angle to a horizontal line, and. also at a time when the dipper is carrying its load. For this reason the tension in the crowding run 11 of the crowding line B, will be increased automatically at a time when it should be at its maximum, and this crowding effect does not depend solelyupon the tension existing in the dipper hoist line D. If

the operatorof' the excavator desires to take a deeper-bite with the dipper than occurs when the teeth follow the arc Ml, he can do so by easing up on the retractor cable C. At this time he can,

tothe crowding cables yield somewhat, he can extend the dipper-stick I0 as described. After the dipper H has picked up its load, of

course the operator movesthe controls to rotate the excavator frame around on the turntable 2, and then dumps the load from the bottom of the dipper by the usual means-not illustrated. At all times the boom 4 can be raised or lowered as desiredyand there is enough slack in the boom cable to insure that there will always be enough cable to maintain suflicient length in the tension loopa Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.

I claim as my invention:

1. In an excavator apparatus, the combination of a frame, a boom supported at its lower end on the frame, sheave means attached to the peak of the boom, a taut boom cable anchored at one end on the frame passing around said sheave means and in a run back toward the frame, means for guiding said run of the cable in a loop adjacent the frame; a dipper, and a dipperstick carrying the same, and supported on the boom, means for taking up and paying out the boom cable at its other end, a crowding cable connected to the dipper-stick and to the bloom so as to exert a downward thrust upon the same, and means associated with the crowding cable including a sheave riding in said loop for imparting tension to the crowding cable from said loop.

2. In an excavator apparatus, the combination of a frame, a boom supported at its lower end on said frame, sheave means carried on the boom adjacent its peak, a taut boom cable anchored at one end to the frame, passing around said sheave means and in a run back toward the frame, means for guiding said run of the cable in a loop adjacent the frame and extending toward the boom; a dipper, and dipper-stick carrying the same, means for guiding the dipper-stick to move transversely to the boom, a crowding cable connected to the dipper-stick and to the boom so as to exert a downward thrust upon the same, and means associated with the crowding cable including a sheave riding in said loop for imparting tension to the crowding cable from said loop.

3. In an excavator apparatus, the combination of a frame, a boom having a connection to said frame at its inner end, a boom cable,'a sheave on the boom guiding the cable in a loop and a run passing back to the frame, for supporting the boom, means on the frame connected to the said run for maintaining the same taut, means for guiding the other run of said cable at a point adjacent the frame so as to form a loop therein extending toward the boom, a cable take-up hoisting drum on the frame on which the other end of said cable is coiled, means including a sheave riding on the inner side of said loop, a dipper-stick supported on the boom with a dipper on its lower end, a crowding cable, means including a sheave for guiding the same, supported on said boom adjacent the dipper-stick, said crowding cable having an upper run extending upwardly from said last named sheave along said stick and attached thereto; and having a lower run dead-ended on the boom; all of said parts co-operating so that the tension in said loop exerts a tension in the crowding cable, thereby exerting a downward thrust force in said stick to maintain the dipper against a bank being excavated.

4. In an excavator, the combination of a boom, sheaves supported on the boom adjacent its peak, a boom cable anchored at one end on the frame, and runni g on said sheaves, means for guiding the boom cable so as to dispose a portion of the same in a tension loop, a drum in which the other end of the cable is wrapped for taking up and paying out the cable to raise and lower the boom, a dipper with a dipper-stick carrying the same, means for guiding the dipper-stick to slide across the boom, a crowding cable dead-ended on the said stick above the level -of the said guiding means and dead-ended on the boom, said crowding cable disposed in a loop extending toward the said loop of the boom cable, and a block between said loops with sheaves thereon on which said loops run; all of said parts co-operating so that when the boom is lowered, the outward move-.- ment of the center of gravity of the boom increases the tension in said first named loop, thereby exerting force to lengthen the crowding loop and impart a crowding force to the dipperstick.

5. An excavator according to claim 4, including a stick-retractor cable connected to the stick at a low point thereon, a brake-controlled drum on which the retractor cable is coiled, all of said parts co-operating to enable the operator of the excavator to pay out the retractor cable to control the crowding effect while the crowding cable is exerting a downward thrust in the dipperstick.

6. In an excavator, the combination of a frame, a boom, means for supporting said boom on said frame at its lower end to enable the boom to be swung up and down in a substantially vertical plane, a boom cable anchored at one end, means mounted on the boom for engaging said cable and cooperating with the same to enable the cable to support the boom in an inclined position, a drum mounted on the frame upon which a run of said cable is coiled, for taking up or paying out cable to raise or lower said boom, means connected with the frame for guiding the boom cable in a tension loop, a dipper-stick with a dipper carried thereby, a guide for said dipperstick pivotally mounted on the boom, and crowding means connected to the dipper-stick and to the boom, including a sheave running in said tension loop, the tension in said loop being increased by increasing the tension in the boom cable when the boom is lowered to pick up the load, thereby increasing the crowding thrust acting on the dipper-stick so as to move the-dipper forward as it takes its load.

'7. In an excavator, the combination of a frame, a boom supported in said frame to swing up and down about a substantially horizontal axis, a boom cable anchored on the frame, a drum on which a run of said cable is wound for raising and lowering the boom, means adjacent the peak of the boom for guiding said cable on the boom, to enable the same to cooperate with the drum to support the boom, means supported on the frame for guiding the boom cable in a tension loop, the tension whereof is maintained by the weight of the 'boom, and increased by the weight of the boom when the boom is lowered to take a load in the dipper, a crowding cable, means for guiding the same in a loop connected to said tension loop to maintain tension in the crowding cable; said crowding cable having a guide sheave on the boom about which it passes, means for anchoring one of the runs of the crowding cable on the boom, and means for anchoring the other run of the crowding cable on the dipper-stick.

8. In an excavator having a frame, a boom supported thereon at its lower end, and a dipper stick crowding cable, the combination of a pair of peak sheaves supported adjacent the peak of the boom, and on opposite sides thereof, a shackle pivotally supported on the frame, a pair of sheaves spaced apart, mounted on said shackle, and a cable anchored at one end and passing around one of said first named sheaves, then back to and around one of said second pair of sheaves, then extending toward the boom on a tension loop, beyond said tension loop passing around the other sheave of said shackle, and thence passing over the other sheave and then passing in a run back toward the frame, and a take-up drum for the cable on which the last named run is wrapped.

BERT CALVERT.

8 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,733,753 Rauch Oct. 29, 1929 2,037,958 Baker Apr. 21, 1936 2,344,796 White Mar. 21, 1944 10 2,384,242 Fitch Sept. 4, 1945 

